Now dating for over a year, the ultra-private, real-life couple opened up about getting acquainted on the horror film, in which they play a flirty but platonic social worker (Zellweger) and psychologist (Cooper).

"Can't say enough about her," Cooper, 35, raved to Entertainment Tonight. "I never met her before this movie, but I just love her. I love coming to work. I love acting with her. I can learn so much from her."

Zellweger, 41, added of her love, "He's a great actor! I just got so excited, not believing that I was going to go work with him." (Lately, Zellweger has been palling around in L.A. with Gloria Cooper, the "A-Team" actor's mom.)

Cooper gushed, "It's just so easy to work with her!"

The couple have been notoriously tight-lipped about their romance. In the June/July issue of Details, Cooper refused to chat about Zellweger. "I just can't," he said.

"They're so down-to-earth and [they] spend time with family whenever possible," a source close to the couple told Us earlier this year. "They're the real deal!" added another pal.